condition mean min max ZT0-3 1.513245 1.513245 1.513245 ZT4-7 1.344445 1.344445 1.344445 ZT8-11 0.9727595 0.9727595 0.9727595 ZT12-15 1.5451000000000001 1.5451000000000001 1.5451000000000001 ZT16-19 1.9543400000000002 1.9543400000000002 1.9543400000000002 ZT20-23 1.386235 1.386235 1.386235